import pandas as pd

file_path = "Beijing.xlsx"

sheet_names = pd.ExcelFile(file_path).sheet_names

dfs = []

for sheet_name in sheet_names:
    df = pd.read_excel(file_path, sheet_name=sheet_name)
    dfs.append(df)

merged_df = pd.concat(dfs, ignore_index=True)

merged_df.to_excel("population_of_Beijing.xlsx", index=False)